This application is based on applications No. 053346/2000 filed in Japan on Feb. 29, 2000, No. 046537/2000 filed in Japan on Feb 23, 2000 and No. 054822/2000 filed in Japan on Feb. 29, 2000, the contents of which are incorporated herein by reference.
The present Invention relates to an electric shaver having a circuit board with electronic parts thereon, and a pair of plug pins projecting from the body casing.
There are two types of electric shaver, i.e. the one having a built-in wire, and the other having a detachable electrical wire.
The latter must be provided with a plug pins protruding from the body casing in order to detachably connect a power source electric wire.
Prior art shavers have a pair of plug pins secured on a plug board and the plug board is firmly retained in the casing so as to secure the plug pins to the body casing.
The plug board needs a set of lead wires connected to the plug pins. Related art shavers have a circuit board provided with electronic parts as well as a plug board, electrically connected to each other but separately secured in the body casing.
The structure of the related art shavers has the drawbacks that assembling worktakes a lot of time because the electronic parts board and the plug board together with electrical wires connecting these boards must be placed into the casing.
The structure also incurs a higher manufacturing cost because of a rather complicated configuration of the casing due to the fact that the casing must be configured so as to receive the parts board and the plug board separately.
There are also washable electric shavers. This type of electric shaver is convenient because the user can wash it, and thus a waterproof electric shaver requires a watertight casing. A watertight structure is easily produced by employing a cylindrical body casing. With a cylindrical casing, a watertight structure is readily achieved by employing watertight sealing means on the upper and lower ends of the casing. However, a cylindrical casing makes it difficult to insert a parts board and a plug board, which are electrically connected to each other by means of electrical wires. Mounting these boards in a cylindrical casing can be facilitated by employing an outer casing and an inner case to be inserted in the outer casing, and the parts board and plug board are mounted on the inner case.
The electric shaver with this structure has the parts board secured to the inner case, and the parts board is electrically connected by means of lead wires of the plug board.
The electric shaver of this structure requires assembling work in which the parts board and plug board are inserted together with electrical wires connecting the boards, and the electrical wires can cause trouble.
In the case where the parts board and the plug board are separately secured to the inner case, the configuration of the inner case becomes so complicated that it results in higher production costs.
The present invention is proposed to overcome these drawbacks. The most important object of the present invention is to provide an electric shaver having a simple structure and yet is easy to assemble with a parts board and plug board secured on the inner case.
Another important object of the present invention is to provide an electric shaver with a plug board firmly secured to the inner case on which plug board are fixed plug pins.
The above and further objects and features of the invention will be more fully apparent from the following detailed description and accompanying drawings.
The electric shaver of the present invention includes an electric motor for reciprocating an inner blade assembly, batteries for supplying power to the motor, an electronic parts board connected to the batteries, an inner case securing the electronic parts board, the electric motor and the batteries are inserted into an outer casing, and a plug pin board securing the plug pins, which protrude from the outer surface of the outer casing.
Furthermore, the electric shaver of the present invention has the construction described below.
The inner case has a lower separating wall integral therewith and made of a plastic, the periphery of which sealingly abuts on the inner surface of the outer casing. The inner case secures an electronic parts board above the lower separating wall. Furthermore, the inner case secures a plug board parallel to the case under the lower separating wall. The electronic parts board and the plug board are connected by metal pins. One end of each of the metal pins is fixed to the electronic parts board and the other is fixed to the plug board. Each of the metal pins pierces through a hole and is retained in the inner case. The outer casing has an open end which is closed by a bottom cover. The bottom cover has a plurality of through holes for plug pins which extend outwardly from the outer casing.
The construction of the electric shaver is characterized by the simplicity of construction and ease of assembly, wherein. the electronic parts board and the plug board are fixed on the inner case and the inner case is then inserted into the outer casing. The advantage of the electric shaver according to the present invention is obtained by the construction wherein the inner case is formed integrally with the lower separating wall abutting on the internal surface of the outer casing, and the electronic parts board and the plug board are connected by metal pins penetrating the lower separating wall. With the simple construction, the electric shaver according to the present invention enables the electronic parts board to be secured on the plug pins in a predetermined position. Using the metal pins instead of lead wires connecting the electronic parts board and the plug board, the shaver according to the present invention eliminates the lead wires connecting the electronic parts board and the plug board thereby facilitating the assembly work.
The outer casing of the shaver according to the present invention is preferably fabricated of a plastic with a tubular configuration. The lower separating wall is provided with an O-ring at its periphery for a watertight connection with the outer casing, while the plug pins are provided with an O-ring abutting on the inner surface of the bottom cover for a watertight connection with the through holes. The construction of the electric shaver of the present invention can be used for a watertight electric shaver.
The electric shaver with a watertight lower separating wall and the bottom cover with watertight plug pins is preferably provided with a safety valve on the bottom cover which functions as a relief valve that is actuated at a predetermined pressure level in a space enclosed by the lower separating wall, bottom cover and the outer casing. The safety valve thus prevents gas from entering the upper block, thereby avoiding damage to electronic parts.
Furthermore, the inner case, which is made of a plastic, has latch means integral with the case to retain the electronic parts board. Thus, the electric shaver of the present invention retains the electronic parts board in the inner case.
The ends of the metal pins of the electric shaver of the present invention are fixed by soldering to the electronic parts board or to the plug board. By this method, the metal pins are secured to the electronic parts board and to the plug board.
The inner case according to the present invention is formed integrally with a tubular case to retain two batteries disposed side by side and in parallel to the electronic parts board. The inner case is preferably formed integral with hub portions for retaining the bottom cover. The hub portions are disposed at hollow spaces between the two cylindrical batteries.
The electric shaver having the construction that the inner case with an integral tubular case, in which batteries are retained, is preferably provided with the retainer having a closed upper end and an open bottom end. The lower ends of the batteries retained in the tubular retainer are connected to lead plates which are in turn connected to the plug pins. The electric shaver is capable of retaining the batteries by means of lead plates and plug pins.